phantom

Dealing with phantom objects, e.g.: - phantom bivalent vertices that are used to simplify modifications - phantom arcs that are used for plotting algorithm to work

Functions

insert_phantom_node(k, arc[, node_name])	Put a "phantom" bivalent vertex on the arc.
insert_phantom_nodes_on_internal_arcs(k, nodes)	insert phantom bivalent vertices on edges that connect two nodes from the nodes set.
is_node_phantom(k, node)